Name:ESXi VIB Acceptance Level Tampering id:d051d94f-c792-445e-b5d2-0b904f93ac09 version:1 date:2025-05-15 author:Raven Tait, Splunk status:production type:TTP Description:This detection identifies changes to the VIB (vSphere Installation Bundle) acceptance level on an ESXi host. Modifying the acceptance level, such as setting it to CommunitySupported, lowers the system's integrity enforcement and may allow the installation of unsigned or unverified software. Data_source:
-VMWare ESXi Syslog
search:`esxi_syslog` Message="*esxcli software acceptance set*" Message="*shell*" | rex field=_raw "\]: \[(?<user>\w+)\]:(?<command>.+)" | rex field=_raw "Z (?<dest>[\w\.]+)\s" | stats min(_time) as firstTime max(_time) as lastTime count by dest user command | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `esxi_vib_acceptance_level_tampering_filter`
how_to_implement:This is based on syslog data generated by VMware ESXi hosts. To implement this search, you must configure your ESXi systems to forward syslog output to your Splunk deployment. These logs must be ingested with the appropriate Splunk Technology Add-on for VMware ESXi Logs, which provides field extractions and CIM compatibility. known_false_positives:Administrators may use this command when installing third party VIBs. Tune as needed. References: drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'ESXi Post Compromise' - 'Black Basta Ransomware' asset_type:Infrastructure mitre_attack_id: - 'T1562' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' security_domain:endpoint
